1. Field of the Invention
The present invention relates to a server system communicating with a personal digital assistant (PDA) and a communication method thereof, and more particularly, to a server system communicating with a PDA, which allows files to be selectively downloaded from the server system to the PDA, and a communication method thereof.
2. Description of the Related Art
Since a PDA includes a central processing unit (CPU), a memory, an input/output device, etc., the PDA processes information by itself, and uploads and downloads file and data on demand when connected to a server system.
In general, a communication system between a PDA and a server system includes a main server, a sub-server connected to the main server via a network, a data transceiver connected to the sub-server, a PDA portion having a plurality of PDAs each connected to a port of the data transceiver, and a PDA connected to another side of the sub-server via a public network in the same manner as the PDA portion. Here, the PDA portion and the PDA can communicate with each other via the public network.
FIG. 1 is a flowchart illustrating a conventional communication method with a PDA.
Referring to FIG. 1, if a file taken from a main server via a file transfer protocol (FTP) corresponds to notice board information distributed to all PDA users (step 100), or is a common file required for all PDA users (step 102), the file is stored in a common file directory (step 104). The file in the common file directory is used for initializing the PDA, and is downloaded to each PDA via the data transceiver.
A file for only a specific user is stored in an individual file directory (step 106), and downloaded to the PDA via the data transceiver when the user initializes their own PDA.
However, in the above communication method using the PDA, when the information content stored in the PDA is changed or the amount of data to be stored in the PDA is increased by adding new information thereto, all files or data cannot be stored due to a limited memory size (about 20MByte) of the PDA. In addition, all files or data are downloaded, regardless of whether the PDA user needs them.
To solve the above problems, it is an object of the present invention to provide a server system communicating with a personal digital assistant (PDA), and a communication system thereof, wherein the PDA is capable of selectively downloading files or data from a server, thereby efficiently using the limited memory of the PDA.
According to an aspect of the above object, there is provided a system including a server system for generating and storing files to be distributed to a plurality of users, a data transceiver connected to the server system, and the PDA connected to the data transceiver, for transmitting and receiving the data of the server system, wherein the server system comprises: a data portion for storing all files; a selector for selecting files to be downloaded to the PDA from among the files provided by the data portion, according to the command of a user; a file storage portion for storing the files selected by the selector; and a controller for classifying the files selected by the selector according to users, storing the files by user in different directories of the file storage portion, and when a user wishes, downloading only files stored in the user directory of the file storage portion to the user""s PDA.
According to another aspect of the above object, there is provided a communication method between a personal digital assistant (PDA) and a server system in a system including the server system for generating and storing files to be distributed to a plurality of users, a data transceiver connected to the server system, and the PDA connected to the data transceiver, for transmitting and receiving the data of the server system, the communication method comprising the steps of: (a) storing files of the server system in the directories of all users, if the files are required by all users; (b) storing files of the server system in a common directory, if the files are new or changed; (c) selecting a file among files of the server system for a PDA user to download to the PDA of a user; (d) finding out the files selected in the step (c) in the common directory and storing the found files in a user""s directory; and (e) connecting the PDA to the data transceiver and downloading the file stored in the user""s directory of the server system.